The disclosure of the above mentioned copending applications are incorporated herein by reference in their entirety. The appropriate components and processes of these patent applications may be selected for, for example, inks and processes of the present invention in embodiments thereof.
The present invention is generally directed to a printing apparatus, treated receiver sheets, and imaging processes thereof. More specifically, the present invention is directed to a color printing apparatus, receiver sheets or substrates that are pretreated with colorless toner and optionally other print quality performance enhancing additives, and imaging processes thereof which provide improved hybrid electrostatographic-ink jet printing processes and improved image properties. The apparatus and processes of the present invention possess a number of advantages such as superior hybrid toner-ink images with excellent resolution, reduced image defects, and print stability properties, such as water and lightfastness properties.
In U.S. Pat. No. 5,847,738, issued Dec. 8, 1998, to Tutt, et al., there is disclosed a process of forming an overcoat on a printed image to provide improved stability comprising: a) applying an image layer on a substrate using a liquid ink to form an imaged element; b) either charging the imaged element to a given polarity or applying a voltage across the surface of the element which is attracted to a conductive surface behind the element; c) applying colorless, charged particles to the element which causes them to be electrostatically attracted to the surface of the image layer; and d) heatfusing the particles to obtain a protective overcoat over the entire surface of the image layer.
In U.S. Pat. No. 5,321,467, issued Jun. 14, 1994, to Tanaka et al., there is disclosed an image forming apparatus comprised of a plurality of different image forming units for recording with different methods. An ink jet recording unit is arranged on the upstream side of an electrophotography recording unit in a transporting path of a recording medium. Recording of the ink jet recording unit is performed prior to that of the electrophotography recording unit.
In U.S. Pat. No. 5,729,785, issued Mar. 17, 1998, to Sakaizawa et al., there is disclosed an image forming apparatus for forming an image on a recording medium including a first conveying path for conveying a recording medium in order to form an image thereon using a first image forming device, a second conveying path for conveying a recording medium in order to form an image thereon using a second image forming device for forming an image according to an image forming method different from an image forming method of the first image forming device, a third conveying path for conveying a recording medium in order to form an image thereon using the first image forming device and the second image forming device, and a setting device for selectively setting one of a first conveying mode using the first conveying path, a second conveying mode using the second conveying path, and a third conveying mode using the third conveying path.
In U.S. Pat. No. 5,612,777, issued Mar. 18, 1997, to Malhotra, there is disclosed an apparatus and method for creating color images which are coated with a composition including a lightfastness inducing material and a hydrophobic polymeric binder which protects the images from rough handling and degradation from exposure to UV radiation in the light.
In U.S. Pat. No. 4,997,697, issued Mar. 5, 1991, to Malhotra, there is disclosed a transparent substrate material for receiving or containing an image which comprises a supporting substrate base, an antistatic polymer layer coated on one or both sides of the substrate and comprising hydrophilic cellulosic components, and a toner receiving polymer layer contained on one or both sides of the antistatic layer, which polymer comprises hydrophobic cellulose ethers, hydrophobic cellulose esters, or mixtures thereof, and wherein the toner receiving layer contains adhesive components.
The following U.S. patents are of interest and disclose, for example, aqueous ink jet ink formulations and imaging processes thereof, that are potentially useful adjuncts to the present invention: U.S. Pat. Nos. 5,180,425; 5,658,376; 5,772,746; 5,630,868; 5,749,950; 4,680,235; 5,672,198; 5,397,807; 5,698,016; 4,994,520; 5,725,647; 5,725,650; and 5,026,427. The aforementioned patents are incorporated by reference herein in their entirety.
The hybrid colorless toner-ink printing apparatus and printing processes of the present invention are useful in many applications including imaging and printing processes, including high quality-low cost per impression multicolor nonimpact printing, for example, thermal ink jet (TIJ), bubble jet, ballistic marking, and acoustic ink printing systems, including digital systems.
Typical dye-based and certain pigment based ink jet inks suffer from deficiencies, for example, in water fastness, smear resistance, light fastness, gloss, and appearance properties, after being printed on various substrates. Pigment based inks can provide an image, on a wide variety of substrates, having high optical density with high water fastness, smear resistance and light fastness, and therefore pigment based are generally preferred to dye based formulations. Nevertheless, the dye and or pigment based ink images are susceptible to print quality defects arising from and inherent in the jetting process, and to variability and idiosyncrasies associated with the receiver substrate media, such as, highly porous media leading to image defects from non-uniform absorption and non porous media leading to smearing. The images typically remain highly vulnerable to environmental image deterioration.
Thus there remains a need for improved image quality and image stability in ink jet type printing devices and processes. These and other improvements are accomplished in embodiments of the present invention and as illustrated herein.
Embodiments of the present invention, include:
A process comprising:
depositing a colorless toner composition onto a charged substrate;
depositing at least one ink image onto the colorless toner and substrate; and
fusing the resulting ink image onto the substrate; and
An image forming apparatus comprising:
a charging device for charging the non-image side of a substrate;
a non-imaging developer housing for depositing charged colorless toner onto the image side of the substrate during charging of the substrate;
an ink image forming device for depositing colored ink images onto the colorless toner residing on the substrate; and
a fuser member for fusing the combined deposited ink image and colorless toner to the substrate.